A&P CHAPTER 19

How many half-moon shaped, pocketlike cusps are found in each semilunar valve?

3

Which of the following would cause a decrease in cardiac output?

An increase in afterload

What would you expect a cardiologist to recommend if there was substantial occlusion to a patient's left coronary artery but not the right coronary artery?

Because this is an important artery, and alternate vascular paths are inadequate, the cardiologist would treat the condition.

Which of the following is not one of the three main factors influencing stroke volume?

Chronotropic agents

What are the cell-to-cell contacts of the cardiac muscle fibers called?

Intercalated discs

The shutting of the semilunar valves occurs during which phase?

Isovolumetric relaxation

Which carries oxygenated blood from the lungs to the heart?

Pulmonary veins

What part of the cardiac conduction system is located in the posterior wall of the right atrium, adjacent to the entrance of the superior vena cava?

SA NODE

Which circuit of the cardiovascular system is responsible for sending blood to the kidneys, stomach, and pelvic regions?

SYSTEMIC CIRCUIT

According to the Frank-Starling law

as the volume of blood entering the heart increases, ventricular contractions become more forceful.

Cardiac output is the amount of blood that is pumped

by a single ventricle in one minute.

What is the sequence of events in the transmission of an impulse through the heart muscle? a: AV node b: AV bundle c: SA node d: Through the atria e: Through the ventricles f: Bundle branches g: Purkinje fibers

c, d, a, b, f, g, e

At the AV node of the conduction system, the action potential is

delayed due to the cells being small and having few gap junctions.

Pectinate muscles are found on the

internal walls of the right and left atria

The posterior interventricular sulcus

is a groove between the ventricles on the back of the heart.

Cardiac output is usually expressed in

liters per minute

The layer of the heart wall composed of cardiac muscle tissue is the

myocardium.

The heart valves

permit the passage of blood in one direction

The base of the heart faces in the _____________ directions.

posterior and superior

Which heart chambers contain deoxygenated blood?

right atrium and right ventricle

The function of the coronary sinus is to

take blood from the coronary circulation to the right atrium.

During ventricular contraction

the semilunar valves open and the AV valves close

The internal wall surface of each ventricle displays large, smooth, irregular muscular ridges called

trabeculae carneae.

The pericardial cavity is between the

visceral and parietal layers of the serous pericardium

The term "epicardium" is another name for the

visceral layer of the serosal pericardium